In general, a car is provided with various lamps, which have a lighting function that allows a driver to easily confirm objects positioned around the car when the car travels at night, and a signal function that informs a travelling state of a car of a driver to drivers of other cars or other road users. For example, a head lamp, a fog lamp, and the like are provided for the purpose of the lighting function, and a turn signal lamp, a tail lamp, a brake lamp, a side marker, and the like are provided for the purpose of the signal function.
In general, a light source, such as a halogen lamp or a high intensity discharge (HID) lamp, has been mainly used as the lamp for a car.
Recently, as the light source, a light emitting diode is being used, a color temperature of the light emitting diode (LED) is about 5,500 K, which is close to a color temperature of sun light, so as to minimize eye strain, and the light emitting diode minimizes a size of the lamp so as to increase a degree of design freedom of the lamp, and also has economic efficiency because of a semi-permanent lifespan.
An attempt has been made to overcome a complicated configuration of the lamp and an increase in process steps in the related art by introducing a light emitting diode, and there is a tendency to extend the lifespan of the lamp using the characteristics of the light emitting diode and overcome problems in terms of a space of the lamp using a small size of the light emitting diode.
In the meantime, a head lamp among various lamps for a car uses various beam patterns, compared to other lamps. For example, a head lamp radiates light having an optimum beam pattern according to a travelling state of a car, for example, a travelling speed, a travelling direction, a road state, and surrounding brightness, to sufficiently secure a view of a driver and prevent drivers of surrounding cars from being blind.
When the light emitting diode is used, one or more light emitting diodes may be used in order to radiate light in each beam pattern and secure a sufficient light quantity.
However, when a size of an aspheric lens is decreased in a head lamp in the related art, efficiency considerably deteriorates, and a size of an optical system is large, so that there is a problem in that it is difficult to mount a plurality of modules within the lamp.